EP 0074810 A2 19830323 - Subscription television system.
Title (en)
Subscription television system.
Title (de)
Abonnement-Fernsehsystem.
Title (fr)
Système de télévision à prépaiement.
Publication
Application
Priority
- JP 14283681 A 19810910
- JP 14283781 A 19810910
Abstract (en)
In a subscription television system, the video signals constituting a specific program has its video portion scrambled in accordance with a predetermined scrambling scheme and a key signal which is used for unscrambling the scrambled video signal is generated in response to the scrambling mode. The key signal is not transmitted until after termination of transmission of the specific program so that correct decoding of the signal in real time is not possible. Various scrambling schemes, including one for the audio part of the video signal are disclosed.
IPC 1-7
IPC 8 full level
G11B 20/00 (2006.01); H04N 5/913 (2006.01); H04N 7/167 (2011.01); G06F 1/00 (2006.01)
CPC (source: EP US)
G11B 20/00086 (2013.01 - EP US); G11B 20/0021 (2013.01 - EP US); G11B 20/00282 (2013.01 - EP US); H04N 5/913 (2013.01 - EP US); H04N 7/167 (2013.01 - EP US); H04N 7/1675 (2013.01 - EP US); G06F 2211/007 (2013.01 - EP US); H04N 2005/91364 (2013.01 - EP US)
Designated contracting state (EPC)
AT BE CH DE FR GB LI LU NL
DOCDB simple family (publication)
EP 0074810 A2 19830323; EP 0074810 A3 19840627; EP 0074810 B1 19870311; AU 562395 B2 19870611; AU 8807282 A 19830317; CA 1200007 A 19860128; DE 3275697 D1 19870416; US 4533949 A 19850806
DOCDB simple family (application)
EP 82304758 A 19820909; AU 8807282 A 19820907; CA 410966 A 19820908; DE 3275697 T 19820909; US 41583682 A 19820908